Answer:
Explanation:
For third normal mode of vibration
l = [tex]\frac{3\lambda}{2}[/tex] , λ is wavelength , l is length of string .
.4 = [tex]\frac{3\lambda}{2}[/tex]
λ = .267 m
velocity = [tex]\sqrt{\frac{T}{m} }[/tex]
T is tension and m is mass unit length
m = .5 x 10⁻³ / 40 x 10⁻²
= .00125 kg / m
Putting the values
velocity = [tex]\sqrt{\frac{80}{.00125} }[/tex]
= 253 m /s
frequency
= velocity / λ
= 253 / .267
= 947.5 Hz .
